Processes of producing oxidized hydrocarbon waxes



Patented July 29, 19 47 UNITED )STATES ATEN OFFICE PROCESSES F PRODUCING OXIDIZED HYDROCARBON WAXES Ernest Stossel, New York, N. Y.

No Drawing.. Application January 20, 1945, Serial N0. 573,806

13 Claims. 1

The present application is a continuation in part of my co-pending United States patent application, Ser. No. 412,597, filed on the 27th day of September, 1941, and entitled Process'of producing high-melting-point waxes and a continuation in part of my co-pending United States patent application, Ser. No. 463,778, filed on the 29th day of October, 1942, and entitled "Processes of producing oxidation products" and also a continuation in part of my co-pending United States patent application, Ser, No. 561,502, filed on the 1st day of November, 1944, and entitled Processes of producing high melting point waxes."

The present invention relates to processes of producing oxidation products from crude oil containing 'a high percentage of wax bearing substances, and more particularly to processes of producing such oxidation products from crude oil tank bottoms.

It is one of the objects of my present inven tion to obtain in 'an efiicient and easy way, by

simple processes, various oxidation products iii-- rectly from dehydrated crude oil tank'bottoms, crude oil emulsions and other wax-bearing substances which contain not only high melting point waxes and heavy oils but also asphaltic ingredients, oxidation inhibiting-constituents and hydrocarbonswhich are liquid at ordinary temperatures, such as light oils and gasoline.

It is a further object of my present invention to avoid the usual solventtreatments for separating the precipitate consisting mainly of high meltthe need of distillation or the necessity of re- I moval of these constituents.

It is well-known that usual wax base stocks produced by reducing tank bottoms, i. e. by the removal of thelight oils and lower melting pointwaxes by distillation, still containheavy oils besides high melting point waxes; in theconventional processes, such heavy oils have to. be removed after distillation by cumbersome, lengthy and expensive solvent treatments before ,the base stocks can be subjected to oxidation.

In order to avoid the presence of asphaltic bodies during distillation, it is known to separate such asphaltic ingredients already before distillation by proper treatment, e. g. with sulphuric acid. However, this does not affect the necessity of solvent treatment after distillation, since the ing point waxes from the heavy oils which treatments are not only cumbersome and expensive but also require very special equipment for the handling of the solvents in order to eliminate losses.

It is still a further object of my present inven tion to produce oxidation products from deposits which settle in the form of emulsions when crude oils containing wax bearing substances are stored.

It is another object of my present invention to greatly simplify and shorten the time needed for production of oxidation products from tank bottoms and similar crude oils by processes which eliminate the necessity of a separate solvent separation step after removal of the light oils and gasoline.

Still another object of my present invention isto provide a process which makes it possible to obtain oxidation products'from crude oil without any solvent treatment with expensiv solvents.

Still a further object or my present invention consists in eliminating the. necessity ofre'moval of' oxidation inhibiting constituentslpresent in obtained wax base stock still contains heavy oils which have to be removed, in the conventional commonly used processes, by separate solvent treatment before oxidation. Thus, in the usual processes for producing oxidizable wax base stocks free of heavy oils, the wax-bearing crude oil is first subjected to an acid treatment to remove the asphaltic ingredients, then reduced to removeth light oils, and finally subjected to a complicated treatment to remove the heavy oils;

this latter treatment-consists usually in dissolving the wax base stock obtained by reduction in an appropriate solvent at an elevated temperature, thereafter cooling or chilling the thus obtained solution to a temperature sufliciently low precipitated substantially oil free wax base stock to effect precipitation of the wax, removal of the by low pressure or vacuum filtration, washing of the thus removed wax base stock with cold solvent, and finally removal of this wash solvent by distillation. It is often necessary to repeat such dissolving, cooling and removal of the wax several times in order to obtain a wax base stock absolutely free of heavy oils.

During all solvent treatments, for instance those described above, it is important that the wax precipitated from the solvent is not too voluminous or porous, does not retain large amounts 7 of solvents and dissolved-oils, and shows good washing qualities. With many types of oils or solvents, it is necessary to add'so-called crystallization modifiers to the waxy oil solution before chilling in order to obtain a slurry which can be filtered without substantial losses. The weight of the solvent present in the so-called dry cake after filtering is sometimes two to four times that of the wax andthis solvent, of course, contains a high percentage of heavy oil; this heavy oil cannot be removed otherwise than by repeated separate washing operation. It is therefore of utmost importance in all solvent treatments to obtain the. wax cake in a compact form showing good washing qualities. v

The most various solvents have been used for solvent treatment; however, since the so-called liquid petfoleum solvents, i. e. the liquid mem bers of the aliphatic hydrocarbon series exercises a marked swelling and solvating effect 'on refined, i. e. deasphaltized micro-crystalline waxes, it was generally assumed that it is inadvisable to use such liquid petroleum solvents for the removal expensive solvents as ethylene dichloride, methyl- '0f heavy oils from waxes; this is the reason that it is customary to use only very specific rather ethyl-ketone andv similar solvents which have only a slight swelling or solving eilect on refined waxes Since, as stated above, such solvents are expensive, complicated processes have to be used to recover them after the treatment so as to eliminate losses of the same.

I have found that I can use for my new processes liquid petroleum solvents, since the presence 7 of asphaltic bodies in the crude oil greatly reduces the congealing tendencies of the amorphous waxes in the-crude oil solution; therefore, such asphaltic bodies are very useful as so-called nets of high molecular weight irom chca raw materials which are available in great quantities.

As described above, in theway proposed by me it is possible to-obtain a precipitate from bydrocarbon residues of the type disclosed which contains mainlyhigh melting point waxes and is substantially treelof so-called-heavy oils. This precipitate may be de-asphalted so as to remove the asphaltic impurities which would inhibit oxidation.

However, I have observed that even such a de asphalted oilfree precipitate obtained from bydrocarbon residues still containseven after it has-been separated from asphaltic impurities and heavy oils-certain oxidation inhibitors which prevent or at least inhibit oxidation of this precipitate if the same is subjected to oxidation by a gas containing oxygen in the usual way,

In order to remove these inhibitors, it has been suggested to subject the hydrocarbons to be oxidized to a separate distillation step, the primary purpose of which is to separate the bulk of the wax from a small percentage of less volatile material which prevents oxidation. It has also been suggested to subject the hydr'ocarbons to be oxi- -dized to a separate refining step by repeated ing and decomposition during distillation or by wax separation aids in case liquid petroleum solvents are used. This is the reason that in case dc asphalted wax base stocks are subjected to solvent treatments, such solvents have to be chosen with particular care so as not to swell or solvate the wax crystals, since as mentioned above the structure assumed by the wax when precipitated from the solvent is of utmost importance.

By using asphalt containing crude oils, tank bottoms or solutions thereof, I am able to use liquid petroleum solvents which are inexpensive and do not require any complicated processes.

It is also well known that there have been many proposals to produce various oxidation products such as acids, aldehydes, 'ketones and alcohols from various type of hydrocarbons, particularly from various waxes. Relatively high quality products have been obtained from purified hydrocarbons, as for instance refined paraffins and waxes, but up to now there was 'no possibility to oxidize hydrocarbon residues such as .tank bottoms containing impurities without at least partial cracking and decomposition of the high boiling point constituents, particularly the 'high melting point waxes contained in the residues.

However, it is of great importance to enabl oxidation of such residues without cracking and decomposition, since the same contain a very highpercentage of hydrocarbons having great chain length and high molecular weight; if oxidized without cracking and decomposition such hydrocarbons would be transformed into oxidized waxes of high molecular weight, great hardness and low viscosity. Therefore, it would be very desirable to enable partial oxidation of such residues, since it would be an easy way to obtain oxidation prodtheir reaction with fuming sulphuric acid which at least partially destroys them. In accordance with my present invention, it is unnecessary to remove oxidation inhibitors from the precipitate to be oxidized; oil the contrary, my new process enables transformation of these oxidation inhibitors into oxidation furthering and activating ingredients: I

This new process is based upon my finding that the oxidation inhibitors contained in a precipitate obtained from crude oil in the manner proposed by me above, consist mainly of higher mercaptans or similar high melting point sulphur compounds which are precipitated during cooling together with the high molecular solid hydrocarbons, particularly the high melting point waxes, and not removed thereafter by any of the usual refining steps. It is known that these mercaptans have a higher melting point than the usual high melting point waxes and are less soluble than the same in most of the solvents used for wax separation; these mercaptans are very resistant to heat treatment and are not removed during a distillation which removes only the lower boiling point hydrocarbons, i. e. the lower melting p int waxes and light oils, but does not attack, i. e. subject to cracking and decomposition the high melting point waxes contained in the precipitate. Such mercaptans are only slightly attacked by the conventional sulphuric acid treatment used for de-asphalting the precipitate and are not removed at all by theclay or fullers earth treatment carried out for bleaching purposes. Thus, it is evident that these oxidation inhibiting mercaptansor similar sulphur compounds are still present in the acid treated and bleached precipitate. Since distillation at high temperatures and pressure and other known treatments used up to date for removal of such'inhibitors would also attack the high molecular weight constituents, particularly the high melting point waxes contained in the precipitate, other means for enabling oxidation despite presence of these mercaptans have to be found.

the solution should also be low,

I have discovered that it is of great advantage to carry out the oxidation of the precipitate oxidation process; addition of such compounds not only eliminates the oxidation inhibiting eflect of the mercaptans but transforms the same into useful oxidation activating factors. This transformation is based upon the fact that certain compounds, particularly oxygen compounds of chlorine, are adapted to react with mercaptans so as to form compounds having a mercaptide like action, 1. e. acting like mercaptides when exposed to oxygen; the thus formed compounds then react with the free oxygen during oxidation like mercaptldes and, as stated above, form certain peroxides or peroxide like compounds which act as catalysts, greatly facilitating oxidation.

With the objects listed in the first paragraphs of this description and also with the additional object of avoiding all disadvantages of the above described known processes, my present invention mainly consists in processes of producing oxidation products from crude oil containing not only wax bearing substances but also asphaltic ingredients'and oxidation inhibiting constituents comprising the steps of heating said crude oil to a temperature at which also the high melting point waxes contained in said crude oil are disand standing without time the crude oil slowly returns to its original pour point and viscosity.

My new process as defined above takes advantage of this so-called hysteresis of the pour point and viscosity of crude oil: by heating the crude oil to a temperature at which all waxes and asphaltic ingredients are dissolved, the pour point and viscosity of the crude oil will be lowered; thus addition of-a .solvent for dilution can often be avoided. If any light oils, e. g. gasoline, are added for dilution, this is done mainly to correct the solved in the same, thereafter cooling said heated crude oil to a temperature at which mainly said high melting point waxes are precipitated from the same while substantially all lower melting point waxes remain in solution, removing the precipitate formed by said cooling, separating the light oils from said precipitate, adding to the thus treated precipitate a small percentage of at least one oxygen compound of chlorine which reacts with the oxidation inhibiting constituents still present in said precipitate, and thereafter subjecting the thus treated precipitate to oxidation in the presence of an oxygen containing gas.

It should be stressed that in order to obtain satisfactory results it is of great importance that the precipitate formed during cooling can separate from the solvent and is coarse enough for its rapid and complete removal.

Therefore, in order to enable formation and separation of the precipitate, the pour point of the solution must be held sufiiciently low during precipitation. Furthermore, the viscosity of preferably not over 100 sec. Saybolt Universal at 100 F. since highly viscous oils cannot be filtered successfully at that temperature at which the precipitate has to be removed.

In conventional known processes these factors, namely the pour point and viscosity, are controlled by the nature of the solvent and the ratio in which it is used. Since all these known procj and viscosity of solutions containing such waxes and oils can be controlled only by the nature and ratio of the solvent used.

Contrary thereto, when as proposed by me crude oil is heated to a temperature at which all waxes and asphaltic ingredients are completely dissolved, the pour point and viscosity of this oil will be temporarily lowered; only after cooling conditions necessary for complete separation and successful filtration of the precipitate used as initial material for the oxidation step.

In this connection, I also wish to emphasize that it is of great importance that the above described. separation of the precipitate is carried out before acid treatment, i. e. before removal of the asphaltic ingredients, since the same greatly reduce the congealing tendencies of the formed wax precipitate and are very useful as wax separation aids. Therefore, the removed wax precipitate occludes almost small percentage of low melting point waxes and thus the amount of heavyoils present in the removed wax precipitate is negligible.

In this connection, it should also be stressed that the light oils forming the main part of the crude oil are excellent selective solvents for the separation of high melting point waxes fromlower melting point waxes and heavy oils when used as described above, i. e. when the precipitation is carried out in the dients.

I- have found that from heated solutions of amorphous waxes in crude oil or crude oil naphtha mixtures still containing asphaltic bodies substantially only the high melting point waxes precipitate together with some asphaltic bodies when these solutions are cooled as described above. I found also that under such conditions the wax precipitate can be easily separated from the crude oil and when filtered, a filter cake is formed which retains only a relatively small amount of solvent, i. e. crude oil, and almost no heavy oils. This filter cake can easily be washed with fresh gasoline to render it absolutely oil free as the asphaltic ingredients still present in the filter cake reduce the congealing tendency of the wax precipitate to such a degree that no swelling or dissolution of the high melting point waxes present in the precipitate takes place while in contact with the cold wash gasoline.

I found that best results for precipitating the wax in filterable form in accordance with my above described process are obtained when the crude oil shows a gravity A. P. I. of at least 30 to 40 degrees or is brought to such a gravity by dilution with higher gravity oils, e. g. light oils or gasoline.

. In this connection, it should be stressed that there is a .definite interrelation between the asphalt contents of'the crude oil or the crude oil solution subjected to precipitation and the required gravity, namely the higher the asphalt contents, the lower the gravity required; this is due to the reduction of the congealing tendencies stirring for a considerable no light oils andonly a presence of asphaltic ingre-' dehydrated, these 7 i. e. for -'the amount of light oil or gasoline to be added all solvent. Thus, it is evident that u crude oils having a low gravity, e. g. crude oil tank bottoms are used as initial materials, the same have to be diluted with light oils. naphtha, gasoline or other appropriate diluents until the obtained solution has a gravity A. P. I. of at least 80 to 40 degrees. I

Crude oil tank bottoms consist of emulsions "of water and crude oil and contain a relatively high percentage of high melting point waxes, l. e. usually frcm to 10%. and purities also asphaltic ingredients. I have found that if such low gravity crude oil emulsions, i. e. crude oil tank bottoms, are dissolved in crude oil or crude oil naphtha mixtures. heated and thereafter cooled as described above, the high melting point waxes contained in the dissolved crude oil emulsions would not form a substantially oil-free precipitate: since the emulsions are very stable, such precipitation would have the result that emulsified crude oil and water together with the high melting point waxes would be precipitated as described above and thus the high melting point waxes could not be obtained free from heavy oil.

Therefore. in case crude oil emulsions are used. it is'oi utmost importance that the emulsions be first broken and the water separated before the bottoms are dissolved in crude. oil of higher gravity or crude oil naphtha mixtures; after the among other im-' water isseparated from the crude oil tank bottoms, i.- e. after the crude oil tank bottoms are dehydrated tank bottoms are diluted with oil of higher gravity, heated and cooled; as result of such cooling, all the high melting point waxes together with a small Percentage of lower melting point waxes and some occluded crude oil will be precipitated; this precipitate will be almost free or heavy oils, as explained above.

It is known to produce waxes from tank bottoms, crude oil emulsions and the like. However, all processes for these purposes contain as main process steps dehydrating and cleaning of the tank bottoms followedvby immediate distillation by which a still bottomis obtained which contains no light oils but still contains all asphaltic bodies and heavy oils besides the waxes. In the usual practice, this still bottom is then subjected to an acid treatment and filtered through clay in order to produce a base stock from which high melting point waxes may be derived. This base stock is thereafter subjected to repeated known solvent treatments to remove the heavy oils. My

processes described in the preceding paragraphs do away with any solvent treatments after distillation and are thus not only much simpler but also substantially less expensive and cumbersome. In connection with above, it should be mentioned that substantially less sulphuric acid and bleaching clay are needed for my new processes than for those known at present, since in the known processes a great percentage of the acid and clay is used up by the heavy oils and soluble asphaltlo ingredients not present in the precipitate obtained by my processes.

I have found that in order to remove all crude oil from the wax precipitate, it is in some cases advantageous to wash the same with cold gasoline so as to render the wax entirely oil free. This can be done without any danger of dissolution or swelling of the wax particles, since enough asphaltic bodies are co-precipitated with the high melting point waxes to reduce the congeal- 8 ing tendencies of the wax while it is in contact with the cold wash gasoline.

I have furthermore found that it is advisable to de-asphaltize and bleach the precipitate before distillation. In accordance with a preferred embodiment of my invention, this de-asphaltixatlon by acid treatment or similar means is preferably carried out before removal of the wash gasoline; in this way, an acid sludge containing the asphaltic ingredients is formed which setties very fast and can be removed easily. It is also possible to bleach the thus obtained waxgasoline solution without removal of the gateline, e. g. by percolating it through a claytower or contacting it with activated clay.

Thereaiter. the precipitate is subjected to a treatment with an oxygen compound ofchlorine which reacts as stated above with oxidation inhibiting constituents still. present in the precipitate. I have found that this oxygen compound of chlorine reacts with the oxidation inhibiting constituents present in the precipitate-whichv hand certain compounds having a mercaptidelike action are formed; these compounds in turn are essential for the formation of peroxides by the free oxygen added during the oxidation step: and such formation of peroxides is of eminent importance, since the same act as catalysts and greatly activate and further oxidation of the wax precipitate.

Thus, it is evident that addition of oxygen compounds of chlorine has a twofold combined effect resulting not only in elimination of the oxidation retarding effects of the oxidation inhibiting constituents present in the wax precipitate but also in the use of these same impurities, particularly mercaptans, for formation of certain compounds which have an oxidation increasing, activating and furthering action.

Various oxidizing agents, particularly oxygen compounds of chlorine, may be used for obtaining the above oxidation activating and furthering effects. As stated above, these oxidizing agents can best be defined by their common action, namely that they react with the oxidation inhibiting constituents, particularly mercaptans, in such a way as to form compounds which in turn react with the free oxygen added during oxidation in such a manner as to form peroxides or peroxide-like compounds which act as catalystsand activate, further and speed up oxidation. I have obtained good results with the most diiferent oxygen compounds of chlorine, particularly chlorites and hypochiorltes.

I have found that for these purposes I can also use any chemical compound adapted to form chlorine peroxide when reacting with the oxidation inhibiting constituents or with an acid, which latter might be added separately, if desired. Such compounds are for instance chlorates of alkalis and alkaline earth metals. Naturally, I may also use chlorine dioxide itself.

It should be stressed that the term oxygen compound of chlorine" as used above and in the following description and claims is limited to and intended to cover only such oxygen compounds of chlorine which are reacting with oxygen inhibiting constituents, particularly mercaptans, so as to form such compounds which react with the free oxygen added during oxidation in such a manner as to form peroxides or peroxide-like further and speedup have to be added.

as catalysts and activate oxidation. I wish also to stress that theterms hypchlocompounds which act rite," chlorite and "chlorates of alkalis andalkaline earth metals" as used above and in the following description and claimshave to be interpreted and are limited in the same manner as the term oxygen compound ofchlorine" defined above.

' As mentioned above, it is advisable to deasphaltize the precipitate before removal'of the light oils. This is usually done in well-known way by I treatment with acid, preferably concentrated sulphuric acid. If such an acid treatment is carried out, this has to be done before addition of the oxidizing agent or agents, as otherwise these oxidizing agents are co-precipitated together with these asphaltic constituents and removed with the sludge, thereby defeating the purpose for which they have been added. It should be mentioned that, if such an acid treatment precedes, the addition of an oxidizing agent or agents adapted to form-chlorine peroxide only when reacting with an acid, it is mostly unnecessary to add a separate acid for purposes of this reaction: the sulphuric acid traces left from the above described sulphuric acid treatment in the precipitate. are sufficient to react with the added oxidizing agent or agents and'to form the chlorine peroxide needed for destroying the oxidation inhibiting impurities still present in the cleaned precipitate.

Although my above described process can 'be .carried out in various ways, I prefer to include into the same the following process steps:

First of all, the crude oil containing wax bearing substances, asphaltic ingredients and water is freed of dirt and water by' any suitable process. Then, the thus obtained dehydrated crude oil is brought to a gravity A. P. I. of atleast to degrees by addition of gasoline or light oils, if it had a lower gravity;

gravity, no gasoline, light oils or other solvents the waxvgasoline solution can be bleached in wellknown way and the wash gasoline removed by heat.

.The thus obtained wax precipitate-if not washed with gasoline-consi'sts mainly oi high melting point waxes, a small percentage of low melting point waxes, light oils, asphalt-1c ingredients, certain oxidation inhibiting constituents and only traces of heavy oils; if washed with gasoline, it is absolutely oil free.

Thereafter, the low melting point waxes and light oils might be removed by heat treatment in well-known way; however, I wish to stress that it is also possible to omit this process step entirely and to remove these ifigredients during -the oxie dation step itself. The thus pretreated percentage of an oxygen compound of chlorine or another compound which is adapted to form such an oxygen compound of chlorine, particularly chlorine dioxide, by reaction with the acid traces left from the in case it has the required This crude oil is then heated in a tank with steam coils or by piping it. through steam heated pipes to a temperature of about 160 to 180 F., i. e. until a clear solution is obtained. This solution might, however, contain small particles of undissolved asphaltic ingredients in suspension; the presence of such asphalt particles in no way impairs the results of my process.

Thereafter, the temperature of the crude oil or crude oil solution is lowered by well-known means to about 10 to 20 F. above that temperature at which the high melting point waxes contained in the heated crude oil are precipitated; during such cooling, it is advisable to keep the crude oil in motion so as to keep the fine particles tling, centrifuging or filtering during which separation the crude oil is cooled to the precipitation 1 temperature of the high melting point waxes. I

prefer to remove the wax precipitate by means of continuous rotary drum type vacuum filters which allow continuous and automatic filtering and washing of the wax cake.

Thereafter, if lighter colors are required, it is advisable to treat the filtered and washed precipitate with about 5% to 10% of concentrated sulphuric acid and to remove the formed acid sludge between 410 and 700, preferably compound of chlorine reacts with the" oxidation inhibiting ingredients, particularly the mercaptans, present 'in the precipitate and forms compounds which not only do not inhibit or retard oxidation but actually form with the oxygen added during oxidation peroxides or peroxide-like compounds having a catalytic action furthering and activating oxidation of the-wax precipitate.

After such admixture of an oxygen compound of chlorine, the obtained mixture is subjected to oxidation in the presence of an oxygen containing gas. Such oxidation results in oxidation products which have a wax-like appearance and are (comparable in many respects to bees, carnauba and montan wax. Thus, most of these oxidation products have a. molecular weight of between 500 and 650, a saponification number of less than 100, and an acid number of less than 25.

As mentioned above, I may use as initial materials for my processes the most diiferent types of crude oils. Thus, the tenn crude oil" as used above and in the following description and claims is intended to define not only crude oils of usual type but to comprehend also tank bottoms, crude oil solutions and emulsions, waxy sediments, and other wax bearing substances which contain, besides high melting pointwaxes, also asphaltic ingredients, oxidation inhibiting constituents and hydrocarbons which are liquid at ordinary temperatures, as light oils and gasoline.

The following examples will most important characterist'c features of my present invention. I wish to stress that these examples are not intended to limit my present inventionto the features disclosed in the same. The scope of my present from East Texas crude oil stored in tanks is separated from water and sand in the usual way by heating to about F. and keeping the oil at this temperature over a period of several days. The water oil emulsion of the crude oil tank bottom is broken by this treatment and the water is then removed.

The dehydrated tank bottom has a gravity A. P.- I. of 32.5 degrees and consists of 56% of ingredients distillable in a vacuum at 4 mm. presprecipitate is then intimately mixed with a small clearly disclose the invention is defined exvclusively. bythe appended claims.

diluted by addinl s or en 11 sure and a temperature oi 650' It, and oi 48% oi ablack residue. v oi about 23% oi ingredients removable by acid treatment. about 40% oi dark brown high melting point waxes and about 87% oi a mixture oi heavy oils and lower melting point waxes.

This dehydrated crude oil tank bottom is then thereto about the double amount oi gasoline having a gravity A. P. I. oi

'65 degrees. thus obtaining a crude oil-gasoline.

solution having a gravity A. 2.1. oi 45.4 degrees. Addition oi this gasoline is combined with heating oi .the dehydrated tank bottom. This is done by pumping the gasoline directly into a steam heated pipe through which the tank bottom is pumped so that a very thorough mixture, i. e. crude oil-gasoline solution having a temperature oi about 175 F" is obtained; in this solution, the tank bottom and also the high melting point waxes contained in the same, are completely dissolved.

This heated solution is then pumped through pipes provided with Jackets ior cooling water. until its temperature is reduced to about 90 to 95 I. At this temperature, the cooled crude oil-gasoline solution is discharged into a slurry tank and iurther cooled in the same during several hours until a iinal temperature oi about 80 F. is reached. The slurry iormed in the tank flows by gravity to a rotary drum type continuous vacuum filter.

The wax cake on the filter is washed with iresh cold gasoline. The thus washed dry cake discharged irom the filter is then heated and pumped in molten state to a treating tank and treated with about 4% oi sulphuric acid at 170 to 180 F. The precipitated sludge is removed.

The thus treated wax precipitate is then sub- Jected in known way to a bleaching treatment with iuiler's earth or activated clay. Thereaiter, the thus acid treated and bleached precipitate is subjected to a heat treatment so as to remove the light oils occluded in the precipitate and the traces oi gasoline leit irom the washing step.

The thus obtained cleaned and bleached precipitate which. however. still contains the oxidation inhibiting constituents oi the original crude oil is then pumped into a reaction t nk where it is slowly heated to about 320 F. When this temperature is reached. about 1% oi an aqueous 50% solution oi sodium chlorite is slowly added to the heated precipitate while passing air through the mixture. Thereaiter. the mixture is held at this oxidation temperature ior about twelve hours; during this time, air is blown continuously through the reaction chamber;

The thus obtained oxidation product might be pumped through a double-pipe cooling system and mixed with gasoline in the same way as described above in connection with dissolving oi the dehydrated crude oil tank bottom. Then, the mixture consisting oi the obtained oxidation products dissolved in gasoline is cooled to about 80 F. and the precipitated slurry is filtered oil; the thus cleaned oxidation product is then This black residue consists i i l is de-asphaltized and bleached as described above. 'Ihereaiter, it is treated with a small percentage oi anhydrous aluminum chloride and clay. Thus. a precipitate consisting mainly oi very light colored yellowish wax is obtained which has a melting point 01' 187' I". and an oil content at less than 1%.

This precipitate is then heated to 280 F. and

' .mixed with between 1% and 2% oi an aqueous stripped oi gasoline by combined heat and steam treatment.

Example 11' 50% solution oi sodiumchlorite and with between one quarter and one heliper cent oi manganese palmitate or manganese stearate. Thereaiter, air is blown through thismixtur'e ior about one hour and the temperature gradually decreased to about 220" I". The mixture is held at this temperature ior about seven hours while the blowing oi air is continued. Then the mixture is leit to settle ior several hours; during settling a very light colored yellowish wax separates irom a small percentage oi a sediment consisting mainly oi catalyst and insoluble materials.

The thus obtained oxidized wax has an. acid number oi 20.7, a saponification number oi 87.5, a melting point of 157 E. a plastic consistency and is very well adapted as a beeswax substitute.

Example III ,A precipitate pretreated as described in Example II istransierred to a reaction chamber where it is heated to 250 F. and kept at this temperature ior eight hours while air is blown through it. Then. about 2% oi anhydrous boric acid is added and the mixture stirred by air while kept at the same temperatue. For stirring the mixture it is also possible to use nitrogen or carbon dioxide instead oi air in order to avoid iurther oxidation while stirring, It is also possible to use instead oi air sulphur dioxide which has a bleaching eiiect.

The oxidation product thus obtained is diluted with gasoline as explained above, cooled and the precipitated wax filtered and stripped oi gasoline.

A very light colored hard wax is obtained; the same has a molecular weight oi 560, a melting point 01 186 I"., an acid number oi 6 and a saponiilcation number oi 60.

Example IV One part oi the oxidation product obtained as described above in Example III is dissolved in six parts oi ethyl acetate and stirred ior two hours while activated carbon is added. The solution is filtered, separated irom undissolved reaction products and thereaiter cooled to F. Then. the obtained precipitate is filtered and the remaining solvent removed by heat and steam treatment.

An almost white wax is obtained the same has an average molecular weigth oi 5'76. a melting point or 194 F'., an acid number oi 8, a saponiiication number of 55, is very hard and in many respects resembles carnauba wax.

It will be understood that each of the elements described above, or two or more together, may also find a useiul application in other types oi oxidation processes dii'iering irom the types described above,

While 1 have illustrated and described the mvention as embodied in oxidation processes using so-called crude oil as initial material I do not.

Aprecipltate obtainedas described inExampleI I6 Without iurther analysis, the foregoing will a 13 so fully reveal the gist of my invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior and desire to secure by bonwaxes from crude oil containing not only wax bearing substances but also light oils, as-

. phaltic ingredients and oxidation inhibiting oop-' stituents comprising the steps of heating said crude oil to a temperature at which also the high melting point waxes contained in said crude oil are dissolved in the same, thereafter cooling said heated crude oil to a temperature at which mainly said high melting point waxes are precipitated from the same while substantially all lower melting point waxes remain in solution, removing the precipitate formed bysaid cooling, separating the light oils from said precipitate, adding to the thus treated precipitate a small percentage of at least one-oxygen compound of chlorine which reacts with the oxidation inhibiting constituents still present in said precipitate, and thereafter tion in the presence of an oxygen containing gas.

2. A process of producing oxidized hydrocarbon waxes from crude oil having a gravity A P. I. of at least 30 to 40 degrees and containing not only wax bearing substances but also light oils asphaltic ingredients and oxidation inhibiting constituents comprising the steps of heating said crude oil to a temperature at which also the high melting point waxes contained in said crude oil are at least substantially dissolved, cooling the thus heated crude oil while keeping it in motion to a temperature at which substantially only said high melting point waxes are precipitated from said crude oil, removing the thus formed precipitate, separating the light oil from said precipiate, intimately mixingwith the thus treated precipitate a small percentage of at leastone oxygen compound of chlorine which reacts with said oxidation inhibiting constituents still present in said precipitate, and thereafter subjecting the thus treated precipitate to oxidation in the presence of an oxygen containing gas.

I 3. A process of producing oxidized hydrocarbon waxes from crude oil having a gravity A. P. I. of

at-least 30 to 40 degrees and containing not only wax bearing substances including not only low melting point and high melting point waxes but subjecting the thus treated precipitate to oxidaalso light oils asphaltic ingredients and oxida-.

tion inhibiting constituent comprising the steps of heating said crude oil to a temperature at which at least all said low melting point waxes are dissolved, thereafter cooling the thus heated crude oil to a temperature of about 85 F., collecting the precipitate formed by said cooling, separating the light oils from said precipitate, adding to the thus treated precipitate a small percentage of chlorine dioxide, and thereafter subjecting the'thus treated precipitate to oxidation in the presence of an oxygen containing gas. 4. -A process of producing oxidized hydrocarbon waxes from paraflln base crude oil containing besides wax bearing substances including high melting point paraflin waxes also light oils asphaltic ingredients and oxidation inhibiting constituents olls contained in said comprising the steps or heating said crude oil to a temperature at which also said high melting point paraflin waxes contained in said crude oil are dissolved in the same, thereafter cooling said heated crude oil to about F. at which temperature substantially only said high melting point paraflln waxes are precipitated, removing the thus formed precipitate, separating the light and thereafter subjecting the thus treated precipitateto oxidation in the presenceof an oxygen containing gas and a small percentage of an oxygen compound of chlorine.

precipitate from the samer 5. A process of producing oxidized hydrocarbon waxes from dehydrated crude oil tank bottom containing besides a very high percentage of wax bearing substances including high melting point waxes also light oils asphaltic ingredients and oxidation inhibiting. constituents, said process comprising diluting said dehydrated crude oil tank bottom with a liquid petroleum solvent, heating said diluted dehydrated crude oil tank bottom to about 180? F., cooling the thus heated diluted dehydrated crude oil tank bottom while keeping it in motion to a temperature at which substan tially only said high melting point waxes are precipitated from said diluted dehydrated crude oil tank bottom while a high percentage of the lower melting point waxes contained in said diluted de-' hydrated crude oil tank bottom remain in solution, removing the thus formed precipitate containing only asmall point waxes while being substantially free of heavy oils, separating the light oils occluded .in

said precipitate from the same, intimately mixing with the thus treated precipitate an oxidizing agent selected from the group of chlorates of al kalis and alkaline earth metals adapted to react. with said oxidation inhibiting constituents still present in said precipitate, and thereafter subjecting the thu treated precipitateto oxidation in the presence of an oxygen containin gas.

6. A process of producing oxidized hydrocarbon waxes from crude oil tank bottom containing besides a very high percentage of wax bearing substances including high melting point waxes also light oils asphaltic ingredients and oxidation inhibiting constituents, said process comprising dehydrating said crude oil tank bottom, diluting said dehydrated crude oil tank bottom with a liquid petroleum solvent, heating said ditank bottom to at luted dehydrated crude oil least 180 F., cooling the thus heated diluted dehydrated crude oil tank bottom while keeping it in motion to between 80 and F. at which temperature substantially only said high melting point waxes are precipitated from said diluted dehydrated crude oil tank bottom while a high percentage of the lower melting point waxes contained in said diluted dehydrated crude oil tank bottom remain in solution; removing the thus formed precipitate consisting mainly of high melting point waxes and containing only a, small percentage of lower melting point waxes while being substantially free of heavy oils, separating the lightoils occluded in said precipitate from the same, adding to the thus treated precipitate at least one hypochlorite adapted to react with said oxidation inhibiting constituents, and subjecting the thus treated precipitate to oxidation in the presence of an oxygen containing gas.

7. A process of producing oxidized hydrocarbon waxes from crude oil tank bottom containing besides a very high percentage of wax bearing substances including high melting point waxes,

percentage of lower melting Q 15 also light oils asphaltic ingredients. water and oxidation inhibiting constituents, said process comprising removing said water from said crude oil tank bottom, diluting'said water-tree crude oil tank bottom with a liquid. petroleum solvent in such a manner as .to obtain a water-tree tank bottom solution having a gravity A. P. I. or at least 85 to 40 degrees, heating lid water-tree tank bottom solution to about l':1., cooling the thus heated water-tree tank bottom solution while keeping it in motion to a temperature being between and I". higher than the precipitation temperature at which substantially only said high melting point waxes are precipitated from said water-tree tank bottom solution, further cooling said pre-cooled water-tree tank bottom solution to said precipitation temperature, separating iromitthe formed precipitate containing only a small percentage 0! lower melting point waxes while being substantially tree or heavy oils, subjecting the thus formed precipitate to a distillation process so as to remove the lower melting point waxes and light oils occluded in the same, and thereafter subjecting the thus treated precipitate to oxidation in the presence oi an oxygen containing gas and a small percentage oi chlorine peroxide.

8. In the process 0! producing oxidizedhydrocarbon waxes from at least substantially waterrree crude oil, the steps of heating said crude oil to a temperature at which the high melting point waxes contained in the same are dissolved, cooling said heated crude oil in the presence oi. asphaltic ingredients irom a temperature at which the high melting point waxes contained in said crude oil are dissolved in the same to a temperature at which substantially all said high melting point waxes and only a small percentage of the lower melting point waxes contained in said crude oil are precipitated from the same, separating the thus formed precipitaterrom said thus cooled crude oil, admixing to the thus obtained precipitate a small percentage 0! an oxygen compound oi chlorine, and subjecting the thus obtained mixture to oxidation in the presence of an oxygen containing gas.

9. A process of producing oxidizing hydrocarbon waxes from crude oil tank bottom containing besides a very high percentage of wax bearing substances including high melting point waxe's also asphaltic ingredients water and oxidation inhibiting constituents, said process comprising removing said water irom said crude'oil tank bottom, diluting thereafter said at least substantially water-free crude oil tank bottom with a liquid petroleum solvent, heating said diluted crude oil tank bottom-to above 180 F.,-cooling the thus heated diluted crude oil tank bottom while keeping it in motion to between 80 and 90 F. at which temperature substantially only said high melting point waxes are precipitated from said diluted crude oil tank bottom while a high percentage of the lower melting point waxes contained in said diluted crude oil tank bottom remain in solution, removing the thus formed precipitate containing only a small percentage of lower melting point waxes and being substantially free of heavy oils, treating said precipitate while in liquid state with concentrated sulphuric acid, removing the resulting sludge, mixing thereafter the precipitate with a small percentage of Y 16 cipitate to oxidation in the presence oi an oxygen containing gas.

10. A process or producing oxidised hydrocarbon waxes irom dehydrated crude oil tank bottom containing besides a very high percentage of wax bearing substances including high melting point waxes also asphaltic ingredients and oxidation inhibiting constituents, said process comprising removing said water from said crude oil tank bottom, diluting therearter said at least substantially water-tree crude oil tank bottom with aliquid petroleum solvent. heating said diluted crude oil tank bottomto above 180' E,

. cooling the thus heated diluted crude oil tank sulphuric acid, removing the resulting sludge,

bottom while keeping it in motion to between 80 and 90' F. at which temperature substantially only said high melting point waxes are precipitated irom said diluted crude oil tank bottom while a high percentage of the lower melting point waxes contained in said diluted crude oil tank bottom remain in'solution, removing the thus formed precipitate. containing only a small percentage of lower melting point waxes and being substantially free or heavy oils, treating said precipitate while in liquid state with concentrated mixing the thus obtained substantially sludgeiree precipitate with a bleaching absorbent agent and steam, removing said bleaching absorbent agent alter bleaching, intimately mixing the thus bleached precipitate with at least one chloriie adapted to react with the oxidation inhibiting constituents still present in said precipitate, and thereaiter subjecting the thus treated precipitate to oxidation in the presence or an oxygen containing gas.

11. A process or producing oxidized hydrocarbon waxes irom crude oil containing not only wax bearing substances but also asphaltic ingredients and oxidation inhibiting constituents comprising the steps oi! heating said crude oil to a temperature at which also the high melting point waxes contained in said crude oil are dissolved in the same, thereaiter cooling said heated ,crude oil to a temperature at which mainly said high melting point waxes are precipitated from the same while substantially all lower melting point waxes remain in solution, removing the precipitate formed by said cooling, adding to said precipitate a small percentage oi. at least one oxygen compound of chlorine which reacts with the oxidation inhibiting constituents still present in said precipitate, and thereafter subjecting the thus treated precipitate tooxidation in the presence or an oxygen containing gas.

12. In the process of producing oxidized hydrocarbon waxes from at least substantiallywater-tree crude oil, the steps or heating said crude oil to a temperature at which the high melting point waxes contained in the same are dissolved, cooling said heated crude oil in the presence of asphaltic ingredients trom a temperature at which the high melting point waxes contained in said crude oil are dissolved in the same to a temperature at which substantially all said high melting point waxes and only a small percentage of the lower melting point waxes contained in said crude oil are precipitated from the same, admixing to said precipitate a small percentage of an oxygen compound oi chlorine,

' and subjecting the thus obtained mixture to oxsubstances selected from the group consisting oi chlorates o1 alkalis and alkaline earth metals, and thereafter subjecting the thus treated preidation in the presence-oi an oxygen containing as.

18. A process of producingoxidized hydrocarbon waxes rromcrude oil containing not only 17 wax bearing substances but also asphaltic ingredients and oxidation inhibiting constituents comprising the steps of heating said crude oil to a temperature at which also the high melting point waxes contained in said crude oil are dissolved in the same, thereafter cooling said heated crude oil to a temperature at which mainly said high melting point waxes are precipitated from the same while substantially all lower melting point waxes remain in solution, removing the precipitate formed by cooling, adding to said precipitatea small percentage of at least one oxygen compound of chlorine which reacts with the oxidation inhibiting constituents still present in said precipitate, subjecting the thus treated pre- REFERENCES CITED The following references are ofrecord in the die of this patent:

UNITED STATES PATENTS Number Name Date 2,119,940 Carr et al June 7, 1938 1,983,672 Labarethe et al. Dec. 11, 1934 2,000,222 Dietrich et al. May 7, 1935 1,788,799 Luther et a1 Jan. 13, 1931 2,186,909 Pollock Jan. 9, 1940 2,370,228 Bruun etal Feb. 27, 1945 2,131,195 Schneider et a1. Sept. 27, 1938 2,308,201 Wiles Dec. 22, 1942 manner 2 

